Weirdly, it was then thought, Tony Blair chose to launch his 2001 manifesto in a school: St Saviour's and St Olave's, Southwark. Perhaps forgetting the traditional affinity between deranged leaders and parties of dumbstruck children, Clare Short said it was an "odd" thing to do. Simon Hughes thought it "bizarre". Alastair Campbell, having choreographed the show, complained that the media "were pretty cynical about the whole event". But it worked well enough for his rivals to want to copy the technique, minus the time-consuming prayers and hymns, and to use it repeatedly ever since.

Nowadays, it's the press conference which has no blameless human wallpaper that looks faintly wrong. Were there problems with the police-check? Why, otherwise, would a visionary not want to emulate Blair, Michelle Obama and David Cameron, and recruit a sea of juvenile extras to reinforce the message of hope and transformation, or in the Queen or Gordon Brown's case, unguessed-at reserves of vivacity? Within the last week, Scottish teens have showcased what a playful prime minister we've just lost, while in a London college pre-voters massed around Nick Clegg, who needed something to illustrate "the biggest shake-up of our democracy" since the Great Reform Act.

But it's when something suspect or disreputable needs to be sanitised, that youth scenery comes into its own. Tasked with passing off his grotesque Olympic mascots as a piece of premier British design, Lord Coe commissioned two of the world's most trusted cynicism deflectors: a crowd of primary school children and an endorsement by Michael Morpurgo. Old enough to say "it's cool" to reporters, but too young to condemn an aesthetic outrage, Coe's children also embodied the revised Olympic message: it's totally about kids. The designer's brief, we learned, was "to create mascots that would excite and inspire young people and encourage them to get involved in sport". Wenlock, named after the Shropshire site of Britain's first Olympic revival, was a special token of this idealistic commitment. Along with his mate, the puppet is expected to raise £15m for Coe's organising committee.

"By linking young people to the values of sport", his lordship announced, "Wenlock and Mandeville will help inspire kids to strive to be the best they can be." Thus, the more the school children contradicted the only possible adult response to these role models (that of reflexive disgust) the more they confirmed that the games are, already, generating near-spiritual fervour in the next generation.

What does it matter if adults can only see a pair of bifurcated mobile phones, with Mandeville's eye-catching groin definition creepily hinting at of mascottian oestrus or, possibly, a urinary tract infection? The characters were not designed to please grown-ups, any more than those comparative beauties, Iggle Piggle from In the Night Garden, or Waybuloo's Nok Tok. If years of CBeebies has taught us anything, it's that the more outlandish the puppet-friend, the more beneficial its company will prove to child development. Coe's mascots may have much to teach us. In a world where we so often judge by appearance, for instance, there is perhaps a virtue in promoting these pitiful creatures that is also consistent with a logo, opening parade and metal tower which promise to make the London games the ugliest in Olympic history. Other than that, however, Coe's "values of sport", as mediated by the mascots, remain elusive, even contradictory. The mascots tell children to "be the best they can be". Yet, as children saw in the Beijing Olympics, being the best you can be is not as good as winning. Far from it. Even 14-year-old British diver, Tom Daley, who impressed supporters just by being there, looked distraught after his best efforts failed, as the Canadians like to put it, to own the podium.

No wonder he was anxious: the head of UK sport, John Steele, described the spectacle of British athletes striving but not winning in Vancouver as "disappointing". It was great, of course, that Amy Williams won gold: "But it did represent the bottom of the medal range. We are not going to sugar-coat the fact that on the targets we set we'd like to have seen closer to the middle of the range."

Targets? Although Wenlock and Mandeville were happy, in their first episode, to scamper about in front of the telly, they will soon, no doubt, be explaining to children why there is no point in a mascot, even an elite one, jumping out of a window and setting off along a publicly funded rainbow if it doesn't have a track record of finding pots of gold. Where 2012 is concerned, sports officials have decided that a fourth place for Britain would be respectable, requiring the winning of 17 gold medals, following appropriate investment. Swimming and cycling are the sports best placed to satisfy these patriots with an improved "market share" of the glory, to use the National Audit Office term.

"The athletes need to be world class to earn extra funding," says Steele, "and we are not here to bail out sports which cannot govern themselves correctly but reward those who show potential." Lots of sports, school children will gather from his grim analysis, are such a waste of space that it's no wonder there's nowhere to play them. In fact, any young people who feel inspired by Lord Coe's twinkling mascots to pursue their own Olympic dream should probably have another think.

It's not for everyone, sport. It's for winners. "Medals are the aim of our funding as we have a responsibility to the British public," Steele explains, though the public was never actually consulted on its investment in his empire. "It is crucial to get as many athletes on the podium as possible."

Although staging this celebration of international fellowship evidently adds to the pressure to beat everyone else, home advantages are thought to offer the host six or seven extra gold medals it might not otherwise have won (which would price ours, I think, at around £1.3bn each). Along with a few east London sports facilities this would, unlike the claimed enhancement of our young folk, at least be an identifiable part of the "legacy" to which Lord Coe and his fellow sports officials incessantly refer.

They must be unaware that the builders of the Dome, which was also justified as an inspiration to the nation's youth, long ago showed that reliance on this word, outside the context of wills, dependably identifies both the speaker and the alleged inheritance as worthless. Back then, Labour would not listen, and the Tories became lucky bystanders at the historic immolation of public funds.

Did they learn anything at all? If so, it is not too late to purge the coming games of their most egregious flourishes and waste. And if not, let these mascots be a warning.